Topic: RX-480 - 31+mh @ 125w at the wall - Modded ROM - HELPING OTHERS (Read 4046 times)

Only on Sapphire Nitro models.

It's possible on every other model, but you'll have to add those offsets yourself  
Which is perfectly possible

All,
If you happen to have the Sapphire RX 470 card you can BIOS mod the core voltage quite easily using a hex editor as described below.
Possibly, this method can be used on other cards, too.

If you mod your BIOS it is at your own risk. I bear no responsibility.

I used HxD to undervolt core of my cards.

I found a recipe on overclock.net on Polaris Bios Editing - http://www.overclock.net/t/1604567/lightbox/post/25523158/id/2873391

Open the ROM BIOS file retrieved from your card in HxD.  Search for string FF 00 01 07 0C 00.
Locate the four bytes just preceeding the above string.   If the first two bytes = 8D 00 then the next two bytes is the VDDC.
Say you want a -75mV undervolt.  Then store the value F4 FF in the two bytes.  The actual value is FFF4 hex, which is -12 decimal.   (-12 x 6.25 = -75)
After edit your BIOS should read:   8D 00 F4 FF FF 00 01 07 0C 00
Save the file and open and save it with Polaris BIOS editor to update the checksum.
Then flash your card.  
After reboot you can verify the lowered voltage using the TPO GPU-Z sofware.
Good luck!

If VoltageObjectInfo has an initialization table for the VRM, it can be added very quickly. You can automate most of it.

Hey, i never understood why, after i invited you to ethOS (we were chummy then), all i heard is you threw a fit and asked for a refund. (And you started ignoring me) Then while we discuss stuff in another thread, you come and invade my thread and then create your own, insulting/denouncing people publicly. I would ask you stop twisting things and creating drama out of it.

Now, i congratulate you for being willing to take your time to help small users for free, like we have been doing in #ethereumOS for months. It's the support channel for ethereum mining distro, but we spend 99% of our time actually helping people set up their rigs and get the most from their cards, several hours a day, everyday.

I'm probably just wasting my time, trying to patch things up, but i had to try.

Regarding the voltage offset set in BIOS. Small time users can just use wattmontool or a pletoras of tools to make it happen. There is no need to have them risk bricking their cards.

I believe it is only of interest to users whom have a large farm, that can't tweak cards one by one. Using this mod, they will save thousands of dollars (maybe even per month), and you denounce people for asking a little something in return. For example, the last mod i sold, the guy ROI'd from the saving i gave him in 2 weeks.

I guess i'm selfish, but if i'm going to save someone 20k USD per year, i'm going to ask for a BTC or something. If you're willing to help them saving that much money without getting something in return, then i applaud you.

Will someone post a rom here eventually to help others?

I am willing to learn how to my rigs using Hexeditor method. So far I had
3 full rigs of RX480 8GB ref
1 rigs of HIS IceQ RX480 8GB. Link: http://www.hisdigital.com/un/product2-933.shtml They had same heatsink design as XFX RX480 GTR. But not sure about pcb side.
2 rigs of XFX RX480 8Gb GTR.

All these cards using Samsung memory chip. So I guess they all had same timing right?
So far I manage to using Hex editor, locate the memory timing. I think i can replace the timing. But I dont expert enough to modify the VDDC for these. Willing to learn how to do it.

Thank you for sharing your knowledge to the community.

Let me clarify, I will help people learn to do their own ROMs.  I am not looking to do 100 different ROMs, I don't have that kind of time.

As Eliovp has pointed out they aren't the easiest thing to do and take time to do correctly.  If someone wants to help themselves I will help them.

I certainly will, Nitro are easy